1. Technical Field:
This invention relates to vacuum circuit interrupters and more particularly to vacuum circuit interrupters with axial magnetic arc transfer mechanisms.
2. Description of the Invention:
A vacuum circuit interrupter is an evacuated container that encloses electrical contacts for carrying a load current in an electrical distribution system. When the contacts are separated, an arc usually occurs during initial moments of the separation. The arc occurs at high power and must be extinguished without damaging the interrupter in order to ensure repetitive operation.
Vacuum circuit interrupters of various types have been developed for preventing localized destruction arc burning damage to the surface contacts during interruption. Typical solutions to problems of dissipating an arc and minimizing damage to a vacuum interrupter are shown in prior art U.S. Pat. Nos. 3,670,129; 4,020,304; 4,079,217; 4,553,002; and 4,618,705. These patents disclose in a vacuum interrupter a magnetic field applied to disburse an arc from the contacts during interruption of a current.
As a result of an ongoing effort to further minimize damage incurred during arcing, an effort has been made to improve the transfer of current to the load terminal during arcing. An overall objective has been to reduce the electrical resistance paths between the movable contact and the outside of the interrupter.